[ python-Bugs-1326277 ] itertools.count wraps around after maxint

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Bugs item #1326277, was opened at 2005-10-13 23:27
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Category: Python Library
Group: Python 2.4
Status: Open
Resolution: None
Priority: 5
Submitted By: paul rubin (phr)
Assigned to: Nobody/Anonymous (nobody)
Summary: itertools.count wraps around after maxint

Initial Comment:
See below.  This goes against the notion of int/long
unification and can cause weird unexpected behavior,
almost like a buffer overflow.  It should promote to a
long at the appropriate time, or that's not feasible,
then raise an exception, don't wrap around silently. 
Xrange is also not so great about this.  It at least
raises an exception if you give it too large an
endpoint, but promoting to long would be better.

Steven D'Aprano and others on clpy pointed this out.

>>> from itertools import count
>>> b=2**31 - 3
>>> c = count(b)
>>> for i in range(5):
...    print c.next()
...
2147483645
2147483646
2147483647
-2147483648
-2147483647
>>>


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